Test script to fix Windows browser detection (https://github.com/substack/browser-launcher/issues/7)

browsers-test.js

var util = require('util')
  , exec = require('child_process').exec
  , execOptions = { timeout: 3000 }
  , wmicCommand = 'wmic datafile where Name="%s" get Version /format:value'
  , rootKeys = ['HKEY_LOCAL_MACHINE', 'HKEY_CURRENT_USER']


// Convenient access to environment variables
var env  = process.env
  , pf   = env['ProgramFiles(x86)'] || env['ProgramFiles']
  , pf64 = env.ProgramW6432 // "C:\Program Files" on x64
  , home = env.USERPROFILE || (env.HOMEDRIVE + env.HOMEPATH)

  // "%USERPROFILE%\AppData\Local" or
  // "%USERPROFILE%\Local Settings\Application Data" (XP)
  , local = env.LOCALAPPDATA || (home + '\\Local Settings\\Application Data')


// Default locations and registry keys
var browsers = {
  chrome: {
    registry: [    // Expanded to HKEY_LOCAL_MACHINE and HKEY_CURRENT_USER
      '"%s\\Software\\Google\\Update" /v LastInstallerSuccessLaunchCmdLine',
      '"%s\\Software\\Wow6432Node\\Google\\Update" /v LastInstallerSuccessLaunchCmdLine',
      '"%s\\Software\\Clients\\StartMenuInternet\\Google Chrome\\shell\\open\\command"',
      '"%s\\SOFTWARE\\Wow6432Node\\Clients\\StartMenuInternet\\Google Chrome\\shell\\open\\command"',
      '"%s\\SOFTWARE\\Classes\\ChromeHTML\\shell\\open\\command"',

      // Parsing this seems to fail, needs testing
      '"%s\\SOFTWARE\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\App Paths\\chrome.exe"'
    ],
    locations: [   // Joined with filename (or [browsername].exe)
      [pf,         'Google\\Chrome\\Application'],
      [local,      'Google\\Chrome\\Application']
    ]
  },
  ff: {
    registry: [
      '"%s\\Software\\Clients\\StartMenuInternet\\FIREFOX.EXE\\shell\\open\\command"',
      '"%s\\Software\\Mozilla\\Mozilla Firefox\\" /s /v PathToExe',
      // First get version, then path
      [ '"%s\\Software\\Mozilla\\Mozilla Firefox" /v CurrentVersion',
        '"%s\\Software\\Mozilla\\Mozilla Firefox\\%s\\Main\\" /s /v PathToExe' ]
    ],
    file:          'firefox.exe',
    locations: [
      [pf,         'Mozilla Firefox']
    ]
  },
  ie: {
    registry: [
      '"%s\\Software\\Clients\\StartMenuInternet\\IEXPLORE.EXE\\shell\\open\\command"'
    ],
    file:          'iexplore.exe',
    locations: [
      [pf64,       'Internet Explorer'],
      [pf,         'Internet Explorer']
    ]
  },

  // Untested and incomplete (Safari for Windows is dead anyway)
  safari: {
    registry: [
      '"%s\\Software\\Apple Computer, Inc.\\Safari" /v BrowserExe'
    ]
  }
}

// TODO: get all paths, merge, then query WMIC
Object.keys(browsers).forEach(function(browser){
  var entry = browsers[browser]
    , file = entry.file || (browser + '.exe')

  // 1st strategy: registry
  if (entry.registry) {
    entry.registry.forEach(function(query){
      var withVersion = Array.isArray(query)
      rootKeys.forEach(function(root){
        if (withVersion) {
          var cmd = 'reg query ' + util.format(query[0], root)
          exec(cmd, parseVersionQuery.bind(null, query[1]))
          return
        }

        var cmd = 'reg query ' + util.format(query, root)
        exec(cmd, parsePathQuery())
      })
    })
  }

  // 2nd strategy: common locations
  if (entry.locations)
    iterate.call({
      browser: browser,
      paths: entry.locations.filter(notEmpty).map(join),
      strategy: 'common location'
    })

  // 3rd strategy: find in PATH
  // - "where" utility is available on > XP
  exec('where '+file, parseWhere, execOptions)

  // Functions (todo: without closures)

  function parseVersionQuery(pathQuery, err, stdout) {
    if (err) return

    var matches = /([\d\.]+)/.exec(stdout.toString())
    if (!matches || !matches[1]) {
      return console.log("can't parse reg version", stdout)
    }

    var version = matches[1]
    rootKeys.forEach(function(root){
      var cmd = 'reg query ' + util.format(pathQuery, root, version)
      exec(cmd, parsePathQuery(function(path){
        found(browser, version, path, 'registry with version')
      }))
    })
  }

  function parsePathQuery(cb) {
    return function(err, stdout) {
      if (err) return

      var matches = /([A-Z]:\\[^"$]+)/i.exec(stdout.toString())
      if (!matches || !matches[1]) {
        return console.log("can't parse reg path", stdout)
      }

      var path = matches[1].trim();
      if (cb) return cb(path);

      getVersion(path, function(version){
        if (version) found(
          browser, version, path, 'registry'
        )
      })
    }
  }

  function parseWhere(err, out){
    if (err) return

    out = out.toString()
      .trim()
      .split(/\s*\n\s*/)
      .filter(drive)

    if (out.length) iterate.call({
      browser: browser,
      paths: out,
      strategy: 'in PATH'
    })
  }

  function join(path) {
    path.push(file)
    return path.join('\\')
  }
})

function notEmpty(path) {
  return path && path[0]
}

function drive(path) {
  return path[1] === ':' && path[2] === '\\'
}

function iterate(version) {
  if (!this.i) this.i = 0

  if (version)
    found(
      this.browser, version,
      this.path, this.strategy
    )

  if (this.path = this.paths[this.i++])
    getVersion(this.path, iterate.bind(this))
}

function found(browser, version, path, strategy) {
  console.log(util.format(
    "\n%s %s [%s]\n  @ %s",
    browser, version, strategy, path
  ))
}

function getVersion(path, cb) {
  // WMIC wants double slashes
  var escaped = path.replace(/\\/g, '\\\\')
    , cmd     = util.format(wmicCommand, escaped) 

  exec(cmd, parse, execOptions)

  function parse (err, stdout, stderr){
    if (err) return cb()

    // "Version=xx"
    var a = stdout.toString().trim().split('=')

    if (a.length===2) cb(a[1])
    else cb()
  }
}

Example output

chrome 35.0.1916.114 [common location]
  @ C:\Program Files (x86)\Google\Chrome\Application\chrome.exe

ff 23.0.1.4974 [common location]
  @ C:\Program Files (x86)\Mozilla Firefox\firefox.exe

ie 11.0.9600.17041 [common location]
  @ C:\Program Files\Internet Explorer\iexplore.exe

ie 11.0.9600.17041 [registry]
  @ C:\Program Files\Internet Explorer\iexplore.exe

chrome 35.0.1916.114 [registry]
  @ C:\Program Files (x86)\Google\Chrome\Application\chrome.exe

chrome 35.0.1916.114 [registry]
  @ C:\Program Files (x86)\Google\Chrome\Application\chrome.exe

chrome 35.0.1916.114 [registry]
  @ C:\Program Files (x86)\Google\Chrome\Application\chrome.exe

ff 23.0.1.4974 [registry]
  @ C:\Program Files (x86)\Mozilla Firefox\firefox.exe

ie 11.0.9600.17041 [common location]
  @ C:\Program Files (x86)\Internet Explorer\iexplore.exe

Upgraded to https://github.com/vweevers/win-detect-browsers